1. Field of the Invention
The present invention relates generally to a vapor separator for an outboard motor and, more particularly, to an improved vapor separator that has a fuel drainage mechanism.
2. Description of Related Art
Internal combustion engines for outboard motors may employ fuel injection systems to improve emission control and fuel economy. Fuel injection systems typically comprise a vapor separator that removes vapor before supplying the fuel to a fuel injector. The vapor separator can have a drainage mechanism to drain fuel accumulating therein for maintenance of the engine or for storage of the outboard motor. For example, U.S. Pat. Nos. 5,375,578 and No. 5,404,858 disclose such drain mechanisms.
Typically, the drain mechanisms include a drain plug threaded into a drain hole located at a lower portion of the vapor separator. In some arrangements, the vapor separator can have a vapor delivery conduit that is directly or indirectly connected to a plenum chamber of an air intake system of the engine to deliver vapor to the intake system for induction. This arrangement is beneficial not only for inhibiting vapor emissions to the atmosphere but also for expediting the drainage of the fuel.
Preferably, the vapor delivery conduit is formed as narrow as possible so that the vapor can be gradually delivered to the intake system such that the impact on the air/fuel ratio is minimized. The narrow conduit, however, decreases the rate of drainage.
A need therefore exists for an improved vapor separator for an outboard motor that permits a vapor separator to communicate with the atmosphere other than through a vapor delivery conduit.
One mechanism could be an atmosphere introduction mechanism that directly introduces atmosphere into the vapor separator. Such a mechanism could be manually operated by a user, operator, mechanic or repairperson. Such an arrangement creates further difficulties.
Typically, the air intake system for an outboard motor comprises one or more intake conduits extending generally horizontally along an engine body of the engine. The vapor separator can be disposed between the engine body and the intake conduit(s). In this arrangement, however, access to the operating member is inhibited because the vapor separator that has the operating member is positioned behind the intake conduit(s).
Another need therefore exists for an improved vapor separator for an outboard motor that can have an atmosphere introduction mechanism that is easily accessible or operable even if the vapor separator is positioned behind an intake conduit(s).
In accordance with one aspect of the present invention, an internal combustion engine for an outboard motor comprises an engine body. A moveable member is moveable relative to the engine body. The engine body and the moveable member together define at least one combustion chamber. An air intake system is arranged to introduce air to the combustion chamber. The intake system includes an intake conduit extending along at least part of the engine body. A fuel delivery system is arranged to deliver fuel to the combustion chamber. The fuel delivery system includes a vapor separator that contains the fuel and removes vapor from the fuel. The vapor separator is disposed between the engine body and the intake conduit. The vapor separator has a drainage mechanism to drain the fuel and an atmosphere introduction mechanism to introduce atmosphere that replaces a volume of the drained fuel. At least the atmosphere introduction mechanism includes an operating member that has an axis along which the operating member moves. The axis does not intersect with the intake conduit.
In accordance with another aspect of the present invention, an internal combustion engine for an outboard motor comprises an engine body. A moveable member is moveable relative to the engine body. The engine body and the moveable member together define at least one combustion chamber. A fuel injection system is arranged to spray fuel for combustion in the combustion chamber. The fuel injection system includes a vapor separator that contains the fuel and removes vapor from the fuel. The vapor separator has a drainage mechanism to drain the fuel and an atmosphere introduction mechanism that is manually operable to introduce atmosphere that replaces a volume of the drained fuel.